A UK port has placed itself at the centre of a revolution in battery technology for shortsea shipping as it seeks novel ways to improve its air quality.
Findings from the 6 month feasibility study at Portsmouth International Port have demonstrated that flow batteries, which store energy in fluid electrolytes, could offer a more cost effective and flexible solution to reducing ships emissions than conventional solid batteries. Flow batteries are less expensive, but larger, than solid batteries per kWh.
The Shore Power for Shipping (SPIDS) project was conducted by Swanbarton and Marine South East, with funding from the Department for Transport’s Transport-Technology Research Innovation Grant (T-TRIG). The SPIDS project has concluded that the flow battery system studied is both scalable and viable, and reduced the peak power of the port’s network connection to only 10-20% of the grid power required using solid batteries. A further study will consider ship design, but calculations indicate the technology is applicable to short-range ships with up to a 100-200 nautical mile range.
Shipping is one of the world’s most polluting forms of transport and can contribute greatly to poor air quality in port towns. Electrification of shipping will greatly reduce emissions but conventional solid batteries are expensive, offer limited energy capacity and require high power from the grid to recharge in short ‘berth times’. The SPIDS research project has concluded that flow batteries could offer a more cost-effective novel approach to the full electrification of short sea shipping.
Flow batteries store energy in fluid electrolytes which are pumped from tanks through the battery’s electrochemical cells as the battery is charged and discharged. The project team has shown that the flow battery’s benefits are scalable and that the energy capacity can be increased through larger electrolyte tanks.
Electrolyte fluids are less expensive per kWh than solid batteries and the onshore recharging of spent electrolyte does not need to be limited to the ship’s berth time which reduces the peak grid power required in the port.
The SPIDS project researched a simulation of a flow battery shore charging system for cross channel ferries visiting Portsmouth. The research details the size and quantity of electrolyte holding tanks that would be required and demonstrates that off-the-shelf pumps and pipes are viable for the installation. The research will pave the way for a study into the deployment of flow battery power on ships and ultimately a trial of the technology on a small vessel with an onshore charging system.
By Jake Frith